High efficiency engine

ABSTRACT

A high efficiency not polluting engine comprises at least a cylinder and at least a piston movable therein, the cylinder including, alternately, a pre-chamber in the cylinder head and/or a chamber for a direct injection mode of operation, the pre-chamber forming a plenum chamber having a size proportional to the swept volume of the engine and to the power to be obtained, the pre-chamber of the chamber being continuously supplied from the outside by pressurized air at a variable pressure controlled by at least two adjustment controls.

BACKGROUND OF THE INVENTION

[0001] The present invention relates to a high efficiency piston engine,which is driven either by pressurized air or other pressurizable gas.

[0002] As is known, are increasingly required high efficiency, nonpolluting engines and, to meet this requirement, several engineconstruction have been already proposed.

[0003] However, prior engines for motor vehicle applications are ratherpolluting and consume a comparatively high amount of fuel.

[0004] Thus, it would be desirable to provide a very simpleconstructional approach which, as applied to a piston engine, wouldprovide said engine with a performance not less than that of an internalcombustion engine.

SUMMARY OF THE INVENTION

[0005] Accordingly, the aim of the present invention is to provide ahigh efficiency, not polluting piston engine.

[0006] Within the scope of the above mentioned aim, a main object of theinvention is to provide such an engine which is very reliable inoperation and which can be used in a broad range of motor vehicles, fora lot of commercial, private and other operations.

[0007] According to one aspect of the present invention, the abovementioned aim and objects, as well as yet other objects, which willbecome more apparent hereinafter, are achieved by a high efficiencypiston engine comprising at least a cylinder and at least a pistonmovable in said cylinder, characterized in that said cylinder has acylinder head including a pre-chamber forming a plenum chamber having asize proportional to the swept volume of said engine and to a power tobe obtained thereby.

[0008] Said pre-chamber is continuously supplied from the outside bypressurized air or other pressurizable gas, at a variable pressure whichis provided by at least two adjustment operations or controls.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Further characteristics and advantages of the present inventionwill become more apparent hereinafter from the following disclosure of apreferred, though not exclusive, embodiment of the invention, which isillustrated, by way of an indicative, but not limitative, example in theaccompanying drawings, where:

[0010]FIG. 1 is a side cross-sectioned view of a prototype of a pistonengine according to the present invention;

[0011]FIG. 2 is an enlarged partial front cross-sectional view of theengine according to the invention, and clearly illustrating an outletvalve thereof;

[0012]FIG. 3 is an enlarged partial front cross-sectional view of theengine according to the invention, and clearly showing an inlet valvethereof;

[0013]FIGS. 4, 5, 6 and 7 are further enlarged partial frontcross-sectioned view of the inlet or injection valve shown in severaloperating steps thereof, according to the invention;

[0014]FIG. 8 is an enlarged, partial cross-sectional view of the engineaccording to the invention, and clearly showing the inlet or injectionvalve thereof; and

[0015]FIG. 9 is a diagram showing the pressure-piston strokerelationship.

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0016] With reference to the number references of the above mentionedfigures, the high efficiency piston engine according to the presentinvention, which has been generally indicated by the reference number 1,comprises, as main components thereof, an engine block 2, including oneor more cylinders 3, each having a cylinder head 4.

[0017] The head 4 of each cylinder comprises at least an outlet valve 5and at least an inlet or injection valve 6, which can be communicatedwith a space 7 formed between the top surface of the piston, or plunger,9, and the bottom surface 10 of the cylinder head 4.

[0018] With reference to FIGS. 4, 5, 6 and 7, the piston engine,according to this preferred, though not exclusive, embodiment of theinvention, operates as follows:

[0019] the pressurized air is injected at a given pressure (X) into thespace between the cylinder head and the piston head.

[0020] This pressurized air injection is automatically performed byexploiting the stroke or displacement of the piston head, which, in theexhausting stroke, before arriving at the top dead center causes thevalve to be pressure opened.

[0021] Thus, the valve will cause the cylinder head pre-chamber, whichis continuously held at said pressure X, to communicate with the pistonhead, which, in the meanwhile, will be arrived at said top dead center.

[0022] The valve, which has a suitably faceted valve stem, facilitates ahigh speed flow of said pressurized air or other pressurizable gasbetween the mentioned portions.

[0023] At the start of the expanding stroke, the valve will be still inan open condition and it will be definitely closed as the piston headwill be displaced by a stroke of about 5 mm beyond the top dead center,in the shown exemplary embodiment.

[0024] A high pressure tank supplies, through a first pressure reducingunit, a second low pressure tank having a volume of few liters, and avariable pressure (for example 15/20 bars) depending on the engine sweptvolume and on the maximum power to be obtained.

[0025] Through a solenoid valve, the mentioned tank will continuouslysupply by exploiting a two-adjustment mode of operation, the mentionedpre-chamber inside the cylinder head.

[0026] Alternately, it would be possible to directly supply the cylinderchamber.

[0027] The first of the two mentioned adjustments (which is a fixedadjustment) controls the minimum RPM of the engine, whereas the secondadjustment is a variable one and bypasses the first, while controllingthe acceleration.

[0028] It has been found that the invention fully achieves its intendedaim and objects.

[0029] Actually, a high efficiency non polluting engine has beenprovided.

[0030] In order to better understand the advantages provided by theinvention, the following practical example would be useful.

[0031] by a piston having a bore of 10 cm and a stroke of 8 cm, aconstant pressure of 1 bar is introduced into the cylinder, therebyproviding on the piston head, from the start to the end of the strokethereof a pushing force (78.5 kg) with the cylinder at an end pressureof 1 bar and with a pressurized air consume corresponding to 0.628liters for each stroke.

[0032] If the pressurized air used in the first 5 mm of the stroke ofthe piston is introduced, then in that space we will have a pressure of16 bars, with a start pushing force on the piston head of about 1.256kg, the end pushing force and air consume for each stroke being heldunchanged with respect to the first example.

[0033] Accordingly, in the first case, we will have an average effectivepressure, with respect to the stroke, of 1 bar and, in the second case,a calculated average effective pressure of about 4 bars.

[0034] Since said average effective pressure is a very importantparameter in calculating the engine power, the great advantage of thepresent invention should be self-evident.

[0035] In practicing the invention, the used supply and outlet systems,as well as the contingent size can be any, depending on requirements andthe status of the art.

1. A high efficiency non polluting piston engine, including at least acylinder and at least a piston movable in said cylinder, comprising,alternately, a pre-chamber in the head of the cylinder and/or a chamber,for a direct injection mode of operation, characterized in that saidpre-chamber provides a plenum chamber having a size proportional to aswept volume of said engine and a power to be obtained thereby, and thatsaid pre-chamber or chamber, in said direct injection mode of operation,is continuously supplied from the outside by pressurized air at avariable pressure obtained through at least two adjustments.
 2. Anengine according to claim 1 , characterized in that the first adjustmentcomprises a pressure adjuster defining a minimum revolution number ofsaid engine, at a fixed pressure, and that the second adjustment, bybypassing the first adjustment, comprises a progressively opened valvewhich controls an acceleration of said engine.
 3. An engine according toclaim 1 , characterized in that the inlet valve, in the absence of adirect injection mode of operation, is designed for communicating saidcylinder head pre-chamber with said piston head, and that said valve canbe automatically displaced depending on the piston stroke inside saidcylinder, by raising the valve, which is held in a lowered positionthereof by the pressure existing inside said pre-chamber.
 4. An engineaccording to claim 3 , characterized in that the raising displacement ofsaid valve causes said pre-chamber to be communicated, through a facetedvalve stem, with said piston head, in the absence of a direct injectionmode of operation.
 5. An engine according to claim 3 , characterized inthat said valve starts to open at an exhausting stroke of said piston,depending on a timing type, and according to a preferred embodiment,before a top dead center and closing after said top dead center.
 6. Anengine according to claim 1 , characterized in that said enginecomprises exhausting valves built-in in the engine head, said exhaustingvalves synchronously operating with the remaining part of the system. 7.An engine according to claim 1 , characterized in that, in the absenceof inlet valves and of said pre-chamber, the continuous supplying fromthe outside by pressurized air or other pressurizable gas is performedthrough a direct injection mode of operation.